A humidity conditioning process performing apparatus that performs an outdoor air humidity conditioning process is known in the conventional art, as disclosed in Japanese Laid-open Patent Application Publication No. 2008-145092. In the art disclosed in Japanese Laid-open Patent Application Publication No. 2008-145092, a refrigerant circuit is provided that comprises a compressor, two heat exchangers, and an expansion valve; furthermore, an adsorbing material, which can adsorb moisture from the air, is applied to the two heat exchangers. When one of the two heat exchangers functions as an evaporator, it functions as an adsorber that adsorbs moisture from the air; furthermore, when the other of the two heat exchangers functions as a condenser, it functions as a regenerator that restores the adsorbed moisture to the air. The present air conditioner supplies humidity conditioned air to the indoor space by performing the outdoor air humidity conditioning process, wherein the heat exchangers repetitively alternate between functioning as an adsorber and functioning as a regenerator.